title: Cytotoxicity of orthodontic materials assessed by survival tests in Saccharomyces cerevisiae.
abstract: The aim of this study was to assess the cytotoxicity of orthodontic materials (brackets, wires, resin, elastomers and silver solder) using Saccharomyces cerevisiae as a model organism. The induction of cytotoxicity was assessed by two different tests using the wild-type S. cerevisiae strain FF18733: (1) direct exposure to orthodontic materials in YPD broth, and (2) exposure to artificial commercial saliva pre-treated with orthodontic materials. Only the silver solder was tested in mutant S. cerevisiae strains to investigate the origin of the observed cytotoxicity. Colony forming units per mL counts were carried out in all experiments and compared to controls to detect significant survival differences. The results showed that only the silver solder induced significant cytotoxicity, which might have occurred via oxidative stress, although this mechanism is not completely understood. Moreover, S. cerevisiae proved to be a reliable and useful model microorganism for evaluating the cytotoxicity of clinical materials.
authors.affiliation: Imunology and Microbiology Lab, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Limberger
authors.forename: Graziela H
authors.initials: GH
authors.lastname: Westphalen
authors.forename: Luciane M
authors.initials: LM
authors.lastname: Menezes
authors.forename: Renata
authors.initials: R
authors.lastname: Medina-Silva
mesh_terms: D015169:Colony Count, Microbial; D003188:Composite Resins / Q000633:toxicity; D003470:Culture Media; D045643:DNA Repair Enzymes / Q000235:genetics; D003722:Dental Alloys / Q000633:toxicity; D003764:Dental Materials / Q000633:toxicity*; D012994:Dental Soldering; D004305:Dose-Response Relationship, Drug; D020724:Elastomers / Q000633:toxicity; D004706:Endodeoxyribonucleases / Q000235:genetics; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D008422:Materials Testing; D050296:Microbial Viability / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D009970:Orthodontics; D018384:Oxidative Stress / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D012464:Saliva, Artificial / Q000737:chemistry; D012834:Silver / Q000633:toxicity; D013193:Stainless Steel / Q000633:toxicity; D013482:Superoxide Dismutase / Q000235:genetics; D000072105:Superoxide Dismutase-1; D013997:Time Factors; D000099156:Superoxide Dismutase 2
chemical_list: D003188:Composite Resins; D003470:Culture Media; D045643:DNA Repair Enzymes; D003722:Dental Alloys; D003764:Dental Materials; D020724:Elastomers; D004706:Endodeoxyribonucleases; D016166:Free Radical Scavengers; D029701:Saccharomyces cerevisiae Proteins; D012464:Saliva, Artificial; D012834:Silver; D013193:Stainless Steel; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000099156:Superoxide Dismutase 2; C084111:Charisma composite resin; C481898:Fill Magic; C000606290:SOD1 protein, human; C083274:Apn1 protein, S cerevisiae